Antitheft and Anti-Overflow Device for Liquid Tank, in Particular Fuel Tank

ABSTRACT

An anti-theft, anti-intrusion and anti-overflow device having a plunger formed of a cylindrical retractable filling tube and a coaxial cylindrical plunger tube. The filling tube slides within the plunger tube between a retracted anti-overflow position and an extended filling position and has a security closure. The plunger tube has a surface with a series of openings to allow liquid to pass through during filling of a tank. The plunger tube has an anti-intrusion device to prevent the passage of foreign devices through the plunger. The plunger is designed to be mounted on a neck component of the tank.

This is a national stage completion of PCT/FR2006/000712 filed Mar. 31, 2006 which claims priority from French Application Serial No. 0503188 filed Mar. 31, 2005.

FIELD OF THE INVENTION

The present invention concerns an antitheft, anti-intrusion, and anti-overflow device for a liquid tank, particularly a tank for motor fuel or combustible fuel—for example, a tank that is carried by a vehicle or one that equips a vehicle.

BACKGROUND OF THE INVENTION

The goal of the invention is to furnish an antitheft device that can be placed on a fuel tank in the same way as the original cap. This device should prevent siphoning from a tank that is equipped with it, as well as any attempt to fraudulently remove fuel or other liquid from a tank.

For safety reasons this device also is designed to prevent the overflow of liquid contained in the tank if the vehicle tips at a wide angle or if the cap is lost. It also prevents liquid from overflowing during the filling process.

This device can be mounted easily on the inlet opening of any type of liquid tank without the need for any modification while still allowing the original stopper to remain in use.

The antitheft device also comprises anti-vandalism features which permit it to retain small foreign objects introduced through the tank cap and prevent them from falling into the bottom of the tank.

Advantageously, this device is simple to manufacture and compact.

The device is particularly well suited for equipping fuel tanks on automobiles and trucks.

To overcome these technical problems, several tank caps have been proposed. For example, anti-intrusion devices exist for preventing the introduction of a conduit for siphoning from the tank.

There are also numerous sealed safety caps blocking access to the tank through the use of a key lock. Generally, this latter type of device does nothing to prevent siphoning from the tank once the cap has been broken.

Thus, in U.S. Pat. No. 4,630,748 in the name of RUSSELL D. KELLER and U.S. Pat. No. 5,476,185 in the name of SNYDER TANK CORPORATION, an anti-siphoning filling device is disclosed which consists principally of a tube attached to the opening of the tank and extending inside it. Lateral openings on this tube allow liquid to pass through for filling the tank, but prevent introduction of a tube or other means of fraudulently removing the liquid. However, this device is not easily adapted to all types of tanks and it has no anti-overflow feature.

A safety cap preventing access to the tank with a simple lock is disclosed in U.S. Pat. No. 5,533,766 in the name of WEBASTON KAROSSERIESYSTEME GMBH. However, it does not prevent the tank from being siphoned once it has been unlocked or broken. Furthermore, since the device is removed to fill the tank, it cannot act as an anti-overflow device.

Finally, there is an antitheft and anti-overflow device maintained in position against the base of the tank and the interior structure of the subsurface of the outlet opening in the tank disclosed in French Patent No. 2,822,889 in the name of the present inventor. However, this device is costly and complex in design and requires a lengthy, difficult installation, making it unresponsive to the technical problem at hand. In particular, it is not intended to be installed as the original tank cap.

SUMMARY OF THE INVENTION

To resolve this technical problem, the device according to the invention comprises a tubular plunger maintained in an immobilized position on the end of the neck of the tank opening by a one-quarter rotation and blocked in position by tamper-proof screws.

The body comprises two coaxial envelopes, preferably cylindrical, a retractable filling tube and a tubular plunger body, forming a coaxial plunging unit. The retractable filling tube is extractable and projects from the plunger tube so as to form a retractable filling tube allowing the tank to be filled to the brim. The tubular plunger comprises an attaching flange that can be screwed onto the end of the neck of the tank opening at the location of the tank cap. This attaching flange is surmounted by an end flange forming a neck for the tank opening for adaptation to the tank cap. In an upper portion, the tubular plunger has transverse openings allowing liquid to pass toward the tank during the filling operation when the retractable filling tube is in the upper position.

If the tank cap is broken or unlocked, these transverse openings are too narrow to allow the introduction of a siphoning tube of sufficient diameter. At the very worst, only the portion of liquid in the upper space located near the transverse openings can be siphoned. With the liquid tank antitheft device of the invention in place, it is therefore impossible to fraudulently remove the fuel occupying the rest of the space in the tank.

Moreover, when the retractable filling tube is in place within the tubular plunger body, it blocks the transverse openings on the tubular plunger, which prevents any overflow of liquid from the tank even if the tank cap is not in place.

Finally, the antitheft device comprises a safety closure, attached to the upper portion of the retractable filling tube, an additional safety feature, which almost totally prevents overflow with the antitheft device equipped with it and prevents liquid in the tank from spilling if the vehicle tips over or flips, or if the cap is lost.

The safety closure of the invention is formed by the end of the retractable filling tube and a movable closure piece which closes the outlet passage in the tube after filling, the closure piece being connected to the tank's sealing cap.

This movable closure piece fulfills the general function of a safety closure. It pivots on an axis that is offset relative to the center of the end opening on the retractable filling tube, allowing it to be opened.

Thus, it provides a supplemental anti-overflow feature.

In addition, despite its simple, compact design, the safety closure, due to its position, also ensures that the retractable filling tube is replaced inside the antitheft, anti-intrusion and anti-overflow device before the tank cap is repositioned.

In this way it prevents the tank cap from being lost.

When the retractable filling tube is in the extended filling position, the retracted position of the pivoting piece constitutes an obstacle that prevents the retractable filling tube from moving back inside the tubular plunger. This feature obliges the user to close and replace the retractable filling tube inside the tubular plunger of the antitheft device in order to be able to close the tank with the original cap.

In addition, the folded down position of the pivoting piece ensures that the retractable filling tube remains in the upper position.

It ensures that the retractable filling tube is all the way inside the antitheft, anti-intrusion, and anti-overflow device before the tank cap is replaced.

The pivoting piece is mechanically connected to the tank cap by some type of connector, a flexible, rigid, semi-rigid, articulated or other type of connector, to prevent loss of the cap. Some examples are a cord or a small chain.

Moreover, by manipulating the tank cap, it is possible to extract the retractable filling tube from the body of the tubular plunger or to introduce it inside the plunger, and it is also possible to pivot the safety piece on the closure in order to open or close it. This manipulation is accomplished by merely touching the external portion of the tank cap, that is, a normally clean part, and then to effect the movements described above without getting dirty by contacting a section or piece that is often wet with fuel.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will be apparent from reading the following detailed description, a description which references the attached drawings, wherein:

FIG. 1 is a perspective view of a first variation of the device according to the invention with the retractable filling tube in the raised position;

FIG. 2 is a perspective view of the first variation of the device according to the invention with the retractable filling tube in the lowered position;

FIG. 3 is a longitudinal cross-section of the first variation of the device according to the invention with the retractable filling tube in the raised position;

FIG. 4 is a longitudinal cross-sectional view of the first variation of the device according to the invention with the retractable filling tube in the lowered position;

FIG. 5 is a schematic longitudinal cross-sectional view of the first variation of the device of the invention attached to the neck of a tank;

FIG. 6 is an exploded perspective view of the first variation of the device according to the invention in a partially disassembled state;

FIG. 7 is a perspective view of a second variation of the device according to the invention with the retractable filling tube in a raised position and with the safety closure of the invention removed for filling;

FIG. 8 is an exploded perspective view of the second variation of the device according to the invention in a disassembled state;

FIG. 9 is a perspective of the second variation of the tubular plunger;

FIG. 10 is an overhead view of the second variation of the tubular plunger;

FIG. 11 is a perspective view of the second variation of the filling tube with a movable closure piece according to a first variation in the open position;

FIG. 12 is a perspective view of the second variation of the filling tube with a movable closure piece according to a first variation in the closed position;

FIG. 13 is a perspective view of the second variation of the safety closure according to the invention with its movable closure portion resting on the rim that receives the cap;

FIG. 14 is a longitudinal cross-section of a different variation of the movable closure piece of the second variation of the filling tube;

FIG. 15 is a longitudinal cross-section of a different variation of the movable closure piece of the second variation of the filling tube;

FIG. 16 is a longitudinal cross-section of a different variation of the movable closure piece of the second variation of the filling tube;

FIG. 17 is a longitudinal cross-section of a different variation of the movable closure piece of the second variation of the filling tube;

FIG. 18 is a perspective view showing the first step of introducing a piece to block inverse rotation by the tubular plunger of the device of the invention;

FIG. 19 is a perspective view showing the second step of introducing a piece to block inverse rotation by the tubular plunger of the device of the invention; and

FIG. 20 is a perspective view showing the third step of introducing a piece to block inverse rotation by the tubular plunger of the device of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The safety device of the present invention will now be described in a detailed fashion with reference to FIGS. 1 through 20. Equivalent elements shown in different drawings will bear the same reference numerals.

FIGS. 1 and 3 show an antitheft device 1 for a liquid tank in the open position. This antitheft device is attached to a liquid tank 2 and fitted to its neck piece 3 defining a filling orifice 4 closed by cap 5.

The antitheft device 1 comprises a coaxial plunger unit 6 formed of two preferably cylindrical and hollow coaxial elements, that is, a retractable filling tube 7 and a tubular plunger 8, forming coaxial plunger unit 6.

Tubular plunger 8 has an upper extremity 9 and a lower extremity 10.

Lower extremity 10 of tubular plunger 8 preferably comprises a blind terminal surface 11 blocked by a closing plate, thus forming a lower area 12 closed at its lower extremity 10 to serve as a receptacle and recovery device for any object or product introduced during an act of vandalism.

However, in another embodiment of the invention, lower extremity 10 of tubular plunger 8 may remain open to allow the passage of liquid.

Upper extremity 9 of tubular plunger 8 is preferably bordered by an attaching flange 13 to be attached and longitudinally immobilized and screwed on so as to prevent rotation like the cap on piece 3 of the neck of filling orifice 4 on tank 2, taking the place of the tank's closing cap 5. This attaching flange 13 is attached to neck piece 3 of the tank filling orifice 4 using tamper-proof screws, for example, such as screws 14, in order to make its disassembly and removal difficult.

Attaching flange 13 on tubular plunger 8 is surmounted by a second neck piece with an end flange 15 forming another neck 16 for filling orifice 4 of tank 2, also adapting to original tank cap 5.

Actually, it is preferable to use the same neck piece as the original one with its two inlet notches 17 and 18 which each admit a tongue spring that conventionally equips the lower surface of a tank cap. This second neck piece 15 is available for sale as a separate unit. The original piece remains on the reservoir neck because it is soldered onto it, while the new neck piece is attached to the old one using the attaching flange. It has the same characteristics, properties, and advantages. Moreover, the end of the neck appears identical, when viewed from a certain distance, to that of a tank that is not equipped with device 1 of the invention.

It is also possible to use the same piece or an analogous piece with a skirt on the lower portion that flares progressively or completely for its entire length or a portion of it, finally attaching to the original neck piece equipped with the attaching flange 13 of plunger 8.

Obviously the neck piece may assume various technical forms depending upon the particularities of the tank or the manufacturer without appreciably affecting the invention. It is also possible to provide a customized one to visually define a tank equipped with device 1 of the invention.

The coaxial plunger unit 6 is immobilized in position on the original neck piece by two diametrically opposed tongue springs on its lower surface which engage in notches provided for this purpose in the neck piece. It is prevented from pivoting after engagement with the notches and a one-quarter rotation relative to the neck piece.

In a preferred embodiment of the invention, the neck piece with end flange 15 may, for example, be joined to attaching flange 13 on tubular plunger unit 8 by lightly soldering it at points or by using a weaker bead of solder designed to break when subjected to mechanical breaking force.

The neck piece with end flange 15 actually projects so as to form a handle for pulling antitheft device 1 from the neck of the tank. Through the use of an attachment means designed to break during a fraudulent attempt to extract antitheft device 1, only this piece can be removed.

It is possible to use any other easily broken means of joining attaching flange 13 to the internal surface of tubular plunger 8 that would function essentially the same way, the goal being that during any attempt to remove antitheft device 1 of the invention, only the neck portion with end flange 15 would be removed and the rest of antitheft device 1 would remain on the neck of the tank.

The other portion of antitheft device 1 remains on the neck of the tank because it is attached to the neck of the tank by upper extremity 9 of tubular plunger 8, and not by the portion of the neck with end flange 15.

Along a certain portion of its lateral surface, tubular plunger unit 8 has transverse openings such as openings 19 of varying sizes to allow liquid to pass through. These transverse openings 19 may be in the form of perforations, piercing, slots, or any other form adapted for the passage of liquid, cut out, broken through, pierced, or perforated through the metal of the lateral wall of tubular plunger 8. In the embodiment shown, these openings 19 are longitudinally oblong in shape or in the shape of longitudinally enlarged perforations.

Retractable filling tube 7 is a tube that is open at both extremities. It slides freely within plunger tube 8 between a retracted, withdrawn position and an extended or raised filling position. For this reason it will hereafter be referred to as retractable filling tube 7.

When tank is in the open position shown by FIGS. 1 and 3, retractable filling tube 7 is placed in the raised position outside of coaxial plunger 6. Its upper portion is open, allowing the introduction and maintenance of the end of a liquid nozzle dispenser while the tank is being filled and allowing liquid to flow through its upper extremity, that is, through an inlet offset towards the exterior.

It is used primarily to support the extremity of the fill nozzle above the opening in order to fill the tank to the brim without difficulty.

Retractable filling tube 7 has a continuous lateral surface. It slides freely but snugly within tubular plunger 8. Therefore, retractable filling tube 7 has a generally smaller diameter than that of tubular plunger 8 which defines a cylindrical receptor housing the retractable filling tube when it is retracted.

A position maintenance means, for example, a one-quarter rotation device with rods or some other type of catch, permits retractable filling tube 7 to be immobilized in the extended position and then released.

In a preferred embodiment, retractable filling tube 7 is locked in the closed or open position by turning it for a one-quarter rotation. It is immobilized in the upper position by means of a catch 20 projecting from its lateral surface on the lower portion which is guided to slide into a longitudinal guide slot 21 shaped like an inverted L formed in the lateral surface of tubular plunger 8. Thus, the vertical bar of the L-shaped slot guides the vertical longitudinal sliding of retractable filling tube 7 along tubular plunger 8, while the horizontal bar of the guide slot 21 allows retractable filling tube 7 to be immobilized in the upper position after it pivots. This vertical bar of the L-shaped slot may have one or more supplemental slots allowing retractable filling tube 7 to be immobilized in other positions.

The course of catch 20 corresponds to the length of guide slot 21, thereby preventing the total removal of retractable filling tube from device 1 by defining an upper limit position.

The diameter of tubular plunger 8 and retractable filling tube 7 must be such that the free space between them is as small as possible so that when retractable filling tube 7 is retracted inside tubular plunger 8, the liquid in tank 2 cannot penetrate through transverse openings 19.

While tank 2 is being filled, retractable filling tube 7 is extended from tubular plunger unit 8 to form a connecting tube for filling. The liquid can be introduced into tank 2 through the upper opening in this tube, serving as a channel flowing towards the tank. The liquid passes through transverse openings 19 in tubular plunger 8 to fill the tank.

Preferably retractable filling tube 7 comprises a gripping means (not shown), for example, a grip or folding handle or some other means, for holding it and lifting it from its housing to place it in upper abutment with the contact rim of the neck piece, corresponding to the extended position.

It is also possible to provide a connecting cord, with a small chain 22 or the like for connecting it to tank cap 5 as shown in FIG. 6 in order to hold the cap and prevent its loss.

According to another variation not shown, another means, for example a spring, may be provided causing the retractable tube to extend automatically, for example, when the tank cap is removed.

The antitheft and anti-overflow device for liquid tank 1 of the invention is shown in FIGS. 2 and 4 in the closed position. In this position retractable filling tube 7 is located inside coaxial plunger unit 6. Its external walls thus come into contact with the internal walls of tubular plunger 8, thereby preventing liquid from flowing through openings 19 provided in this envelope.

Preferably, in this closed position, retractable filling tube 7 is almost totally housed within coaxial plunger unit 6. Only the gripping means in the form of a grip, handle, connector, or the like projects into the neck or is folded inside it so it can be grasped, allowing the retractable filling tube to be partially removed from its housing.

According to a more complete variation of the invention, the retractable filling tube may also enclose an anti-penetration device 23, the purpose of which is to permit the flow of liquid while preventing the introduction of a conduit, especially a flexible conduit, or any other means of siphoning the tank.

In a first preferred embodiment of this variation, shown in FIGS. 3 through 6, anti-penetration device 23 comprises a closure device 24 extending around a generally longitudinal support shaft 25 connected to the internal wall of plunger tube 8 and at a distance from it so as to be generally located in the central longitudinal position. This support shaft holds closure device 24, which may take the form of one closure piece or a plurality of closure pieces 26 constituting an anti-penetration closure unit formed, for example, by superimposing in angular offset positions closure pieces 25 in star formation, using blades or radial paddles, straight or alternately curved inward in one direction and then the other, or any other arrangement, for example staggered or in zigzag formation, making it difficult or even impossible to introduce a siphoning tube into the tank, but allowing liquid to flow at a steady rate during the filling process.

Closure unit 24 is formed so that a path or several tracks remain free to allow the natural or forced flow of liquid, but it is so angular, complex, and convoluted that the insertion of any siphoning tube, even a flexible one, is difficult or even impossible. One example of such a closure device has been shown in perspective in FIG. 6. Many other technical forms may be used to operate in the same general way and produce the same results.

This anti-penetration device makes it particularly difficult or even impossible to introduce any tube or similar means, even a flexible or narrow one, towards transverse openings 19, and thereby completely prevents siphoning, even from the top portion of the tank.

Closure device 24 may not be as long as the height of the area where openings 19 are located. Support shaft 25 may comprises a float 27 sliding freely along the shaft as shown, so as to further block access to the lower portion of plunger tube 8.

In a second preferred embodiment of this variation shown in FIG. 8, anti-penetration device 23 also comprises a closure unit 24 formed by positioning blocking pieces 26, 28 in an angular offset arrangement. In this second embodiment, closure unit 24 is connected to plunger tube 8 by one or more longer closure pieces 28, the unattached ends of which are connected to the internal wall of plunger tube 8.

In another embodiment of this variation, closure unit 24 may be made in another way, for example, in the form of a unit that is permeable by pressurized liquid but impenetrable by even a flexible conduit.

Some examples to cite are a mass of metal bands, a piece perforated by diverging internal conduits, zigzag elements, pieces with offset passageways, entangled bands, rods or other elements constituting successive obstacles to penetration by a siphoning tube.

In the two variations above, when closure unit 24 comprises superimposed angularly offset closure pieces 26, 28, a supporting and reinforcing ring may be attached, for example, in the upper portion of closure unit 24 around closure pieces 26, 28 in order to prevent the latter from being forced or twisted by an exterior tool, for example, a screwdriver. Such a support ring serves both to rigidify closure pieces 26, 28 and to prevent introduction of a tool between closure pieces 26, 28 and the internal surface of plunger tube 8.

Such a support ring is generally soldered to the internal wall of plunger tube 8.

In the situation where closure pieces 26, 28 are formed of blades arranged in a six-branch star, the support ring may be hexagonal in shape with its largest internal diameter being generally larger than the largest external diameter of closure pieces 26, 28.

According to another variation of the invention, not shown, the retractable filling tube may also surround an anti-overflow valve that is movable and slides freely within the retractable filling tube so as to form a contact seal with a lower abutting surface presented by the anti-penetration device 23 as liquid rises in retractable filling tube 7. This function may be fulfilled by float 27 shown in FIG. 7 or by any other movable closure piece with or without closure unit 24.

Thus, in a preferred embodiment of this variation combining these two latter alternatives, the same support shaft 25 simultaneously comprises anti-penetration device 23 and also carries the sliding anti-overflow valve higher. Thus, when the tank is full or in the process of being filled, this anti-overflow valve float, sliding freely but guided inside the retractable filling tube, is pressed tightly against the lower surface of anti-penetration device 23 as liquid rises in the retractable filling tube. This makes it impossible for any liquid to overflow from the tank during filling and prevents any overflow of liquid from the tank after filling, or for another reason.

In addition to or instead of the anti-overflow valve, it is also possible to conceive of another device ensuring the anti-overflow function among other things.

Therefore, according to a second essential variation of the invention, retractable filling tube 7 possesses a safety closure 29 comprising a movable closure piece 30.

In the closed position, movable closure piece 30 ensures the closing of the upper opening of retractable filling tube 7 and that of the tubular plunger in order to close their outlet passageway.

The closure piece is movable in different ways.

In a first preferred embodiment of this variation of the invention, shown in FIGS. 7 through 14, movable closure piece 30 is a piece mounted pivotably about a longitudinal axle like a pivoting safety closure.

Such a pivotably mounted piece 31 comprises a flat piece similar in shape to the upper opening of retractable filling tube 7. Here it is preferably a disc with a diameter generally larger than that of the upper opening of retractable filling tube 7.

In this first embodiment, movable closure piece 30 is pivotably mounted about the longitudinal axle offset from retractable filling tube 7, the axle preferably being a metal shaft 32 traversing pivoting piece 31 with an enlarged rivet-type head 33 abutting the internal surface 34 of retractable filling tube 7.

In order for movable closure piece 30 to remain connected to retractable filling tube 7, the upper portion of metal shaft 32 with maintenance head 33 is larger in diameter than opening 35 in movable closure piece 30. In a preferred embodiment of the invention, a metal washer 36 may be housed between maintenance head 33 of metal shaft 32 forming the axis of rotation and the upper surface 37 of movable closure piece 30.

According to the first preferred embodiment of this variation of the invention, the lower surface 38 of movable closure piece 30 comprises a projecting stop 39, preferably in the form of a vertical catch, serving as a stop when movable closure piece 30 pivots to open and close. This projecting stop 39 is attached near the rim of movable closure piece 30 and metal shaft 32 so that when movable stop piece 30 pivots to open or close, it butts against internal wall 34 of retractable filling tube 7 when movable closure piece 30 is in the closed position or when it has pivoted to the maximum open position.

During the pivoting of movable closure piece 30 and extension of retractable filling tube 7, projecting stop 39 allows movable closure piece 30 to be blocked in a position such that the opening of retractable filling tube 7 is maximal.

During the pivoting of movable closure piece 30 and the introduction of retractable filling tube 7 inside tubular plunger 8, the projecting stop permits movable closure piece 30 to be blocked in a position such that the opening of retractable filling tube 7 is completely blocked by movable closure piece 30. In this case, projecting stop 39 ensures that movable closure piece 30 is securely in place for fulfilling its anti-overflow role.

When movable closure piece 30 is pivoted so as to leave the opening of retractable filling tube 7 free as shown in FIG. 13, it is moved to the side of retractable filling tube 7 and therefore prevents the tube from retracting into tubular plunger 8 and the placement of tank cap 5. This guarantees that retractable filling tube 7 is completely back inside tubular plunger 8 after the filling operation and before tank cap 5 is replaced.

In a second embodiment of this variation of the invention, shown in FIG. 15, movable closure piece 30 is a piece 40 that is pivotably attached to a transverse axle 41 on retractable filling tube 7 like a flap. In this embodiment, a repelling force maintains movable closure piece 30 in closing position toward the top against a rim 42 forming an interior shoulder for retractable filling tube 7 that serves as a seating for movable closure piece 30.

According to this second embodiment of this variation of the invention, opening movable closure piece 30 can be accomplished by introducing the fuel distribution nozzle when filling the tank.

In a third embodiment of this variation of the invention shown in FIG. 16, movable closure piece 30 is formed of two pieces 43, 44 facing each other each pivotably attached to a transverse axle 45, 46 on retractable filling tube 7, respectively, like two flaps. In this embodiment, a repelling force maintains each of these two pivoting pieces 43, 44 in closed position toward the top against a rim 42 forming an interior shoulder for retractable filling tube 7 that serves as a seating for the two pieces 43, 44 of movable closure piece 30.

In this embodiment, the staggered formation forms a seal between the two pivoting pieces.

In a fourth embodiment of this variation of the invention, shown in FIG. 17, movable closure piece 30 is a piece 47 pivotably mounted on a central transverse axle 48 on retractable filling tube 7 like a butterfly. A repelling force maintains movable closure piece 30 in closed position against a semi-circular interior rim 49 and a semi-circular exterior rim 50 forming an interior shoulder for retractable filling tube 7 which also serves as a contact stop for movable closure piece 30.

Generally speaking, whatever the embodiment of this variation of the invention, the upper extremity of retractable filling tube 7 may have one or more rims forming an interior shoulder to serve as a seating for movable closure piece 30 in its closing position.

Preferably, movable closure piece 30 may be a folding component and/or an interior or exterior removable component.

Movable closure piece 30 is permanently attached to gas cap 5 by some sort of connector. This should preferably be a flexible deformable connector. It is more preferable for this flexible and deformable connector to be a cord or an articulated connector 22.

In a preferred embodiment of this variation of the invention, connector 22 is a small metal chain 51, the lower end of which is attached to the upper surface 37 of movable closure piece 30, while its upper end is connected to the lower surface 52 of the gas cap.

In the first embodiment of this variation of the invention, flexible and deformable connector 22 is attached to the upper surface 37 of movable closure piece 30 near the edge of that piece, and essentially opposite support head 33 of shaft 32.

Tank cap 5, through the intermediary of flexible and deformable connector 22, serves as a grip for opening retractable filling tube 7 by pivoting movable closure piece 30, and also allows retractable filling tube 7 to be raised from its housing until it is locked, after a one quarter turn, by rods or other means, corresponding to its raised position.

Flexible and deformable connector 22, in addition to its function of transmitting lifting motion, also prevents loss of tank cap 5.

Once in place on the upper opening of retractable filling tube 7 and that of tubular plunger 8, as shown in FIGS. 12 and 14 through 17, movable closure piece 30 acts as a supplemental anti-overflow safeguard; even if cap 5 is lost despite being connected to it, liquid is prevented from flowing out.

In a preferred variation of this embodiment of the invention, the upper portion of attaching flange 13 of the tubular plunger has one or more passageways 53 traversing it to allow any fuel that might be present in the upper area of tubular plunger 8 on the upper surface of attaching flange 13 to drop back into tank 2. In actuality, a user might inadvertently cause fuel to flow on the outside of retractable filling tube 7 and drop onto the upper portion of attaching flange 13 of tubular plunger 8.

In this variation, movable closure piece 30 has one or more peripheral extensions 54 on its rim which cover orifices 53 traversing the upper portion of attaching flange 13 of tubular plunger 8 when movable closure piece 30 is in closing position on the outlet of tubular plunger 8 and that of retractable filling tube 7. For this reason peripheral extensions 54 on movable closure piece 30 are similar in shape to orifices 53 traversing the upper portion of flange 13, with a slightly larger surface than the latter orifices.

Thus, in this variation, when retractable filling tube 7 is removed from tubular plunger 8 using flexible deformable connector 22, movable closure piece 30 is raised and orifices 53 traversing the upper portion of attaching flange 13 on tubular plunger 8 are freed, thereby allowing any quantity of fuel that may have collected at this level to pass through those openings and return to tank 2. Similarly, when retractable filling tube 7 is repositioned within tubular plunger 8 and movable closure piece 30 again covers their respective upper openings, peripheral extensions 54 on movable closure piece 30 cover openings 53 traversing the upper portion of attaching flange 13 in order to prevent any liquid from flowing through them and into tank 2.

Movable closure piece 30 can be used to maintain retractable filling tube 7 in a quasi-raised position, as shown in FIG. 13. Actually, by making it pivot against the edge of the neck piece on end flange 15 of tubular plunger 8 receiving cap 5, it constitutes a stop by sliding down retractable filling tube 7. Additionally, it must be folded down in order to descend along retractable filling tube 7.

With reference to FIGS. 6 and 8, which are perspectives of essential variations of device 1 according to the invention in a partially disassembled state, we will proceed to describe one example of the installation and use of an antitheft, anti-overflow device for a liquid tank 1 according to the invention.

Installation of device 1 according to the invention takes place according to the following steps:

removal of original gas cap 5;

introduction of device 1 of the invention through the filling orifice of tank 2 generally along an axis perpendicular to the plane of the tank opening;

positioning of attaching flange 13 of tubular plunger 8 on the neck piece of the filling orifice of the tank;

immobilization of attaching flange 13 of tubular plunger 8 onto the original neck piece by rotating the flange a one-quarter turn;

verification that device 1 of the invention is effectively immobilized on the original neck piece of the filling orifice;

attachment of attaching flange 13 on the tubular plunger onto the original neck piece using tamper-proof screws 14 or some other means;

mounting of new neck piece 15 on the unit formed of the original neck piece and attaching flange 13;

replacement of original gas cap 5.

Once positioned, device 1 cannot be removed without ruining tank 2.

In a supplemental variation of the invention shown in FIG. 18 through 20, attaching flange 13 on upper extremity 9 of tubular plunger 8 may be blocked from rotation on neck piece 3 of reservoir 2 using a blocking piece 55. This blocking piece 55 is in the form of a clamp with a rounded extremity 56 and an opposite extremity with a projecting wedge 57 extending perpendicular to the body of the body of the clamp.

As can be seen in FIGS. 18 through 20, which represent the steps in installing blocking piece 551 rounded extremity 56 of blocking piece 55 is introduced through a slot 58 formed in attaching flange 13 of upper extremity 9 of tubular plunger 8, then tilted 90° until the edge of wedge 57 on blocking piece 55 comes into contact with the upper surface of attaching flange 13.

When positioned this way, blocking piece 55 blocks reverse rotation by tubular plunger 8, which prevents device 1 of the invention from escaping from neck 3 of the orifice of reservoir 2.

To further tamper-proof the unit, blocking piece 55 may additionally be attached, for example, with rivets, in order to be maintained in place by a rivet introduced through an opening 59 in the rim of wedge 57 and a sub-adjacent opening in neck 3 of the orifice of tank 2.

To use the device according to the invention when filling the tank, the following steps are followed:

removing original gas cap 5;

freeing retractable filling tube 7;

raising retractable filling tube 7 from plunger 8 using the grip or cap 5 connected to retractable filling tube 7 by a flexible and deformable connector 22;

immobilizing and blocking retractable filling tube 7 in the upper position outside of tubular plunger 8 by a rotating it a one-quarter turn;

filling tank 2 with the distribution nozzle in the upper position inside retractable filling tube 7;

returning retractable filling tube 7 inside tubular plunger 8, and

replacing original gas cap 5.

When filling tank 2, retractable filling tube 7 serves as a guide, a channel, an extension to the outside and a conduit for introducing liquid through a projecting liquid inlet. It allows the end of the nozzle to remain in the upper position during the entire filling process for complete filling. If it foams or becomes too full, the stop on the floating anti-overflow valve contacting the anti-penetration device prevents any liquid overflow or spillage.

It should be noted that the elements constituting the device of the invention must be made of the appropriate material. This material must be sufficiently rigid and resistant to force and the pressure of liquid in the tank. In the case of a fuel tank, for example, the elements of the anti-theft and anti-overflow device might be made of stainless steel or rigid plastic that is resistant to hydrocarbons.

It will be noted that the device according to the invention, in its preferred embodiments, responds completely to the requirements cited above.

Other modes of embodiment may be conceived by a person skilled in the art without departing from the general principle of the invention.

The anti-theft, anti-overflow device described is preferably cylindrical in shape. This appears to be the best adaptation because of the generally cylindrical shape of tank openings, but other adaptive shapes are possible. Therefore, it is possible, for example, to use elements with a square, polygonal, oval, or other section without departing from the general principle of the invention.

Additionally, it is possible to envision various eventual improvements on the device according to the invention without departing from the scope of protection defined by the claims.

For example, it is possible to conceive of placing a spring between the retractable filling tube and the cylindrical internal envelope to constitute a recall force to close the tube, or conversely, to constitute a thrusting force for pushing the retractable filling tube out of the tubular plunger when the cap is removed, or both simultaneously.

It is also possible to provide a gauge on the device, for example, using displacement by float 27 on the anti-overflow valve. A system alarm could also be adapted to the device of the invention to signal any attempt at vandalizing and siphoning the tank.

Furthermore, in order to further enhance security of the device, a sensor could be attached for detecting the presence of a nozzle in the anti-theft, anti-intrusion and anti-overflow device, the presence detector either allowing or preventing the start of filling operation.

Finally, this antitheft and anti-overflow device is designed for liquid tanks. However, this application need not be restrictive and the device could be used in other domains and applications after undergoing some simple adaptations obvious to one skilled in the art. For example, the device of the invention can be adapted to containers for fluid, pulverized, semi-liquid, viscous, paste, or granular material. 

1-32. (canceled)
 33. An anti-theft, anti-intrusion, and anti-overflow device for a liquid tank comprising: a coaxial plunger unit (6) having a cylindrical retractable filling tube (7) and a cylindrical plunger tube (8); the filling tube (7) being slidable inside the tubular plunger (8) and movable between a retracted anti-overflow position and an extended filling position in which the filling tube (7) projects to an exterior and serves the tank (2) as an external filling conduit; the plunger tube (8) having on a lateral surface, at a desired height at a level of an upper space, a series of openings (19) for the passage of liquid during filling, the openings (19) define an upper filling space which is in fluid communication with the tank (2), a lower space (12) of the plunger tube (8) being closed on at least the lateral surface; the coaxial plunger unit (6) being attached to an original neck piece (3) of the tank (2) instead of a gas cap, and the new neck piece (16) defining a new tank filling orifice (4) and being compatible with an original tank filling device.
 34. The device according to claim 33, wherein the lower space (12) of the plunger tube (8) is closed for collection and recovery of at least one of objects and products introduced through the new neck piece (16), and to form, between the upper filling space and the lower space (12), a limit to block introduction of a conduit that might be forcibly introduced through the new neck piece (16) of the anti-theft, anti-intrusion, and anti-overflow device.
 35. The device according to claim 33, wherein the upper filling space in the coaxial plunger unit (6), in fluid communication with an internal tank space, is occupied by an anti-penetration device (23).
 36. The device according to claim 35, wherein the anti-penetration device (23) of the coaxial plunger unit (6) is a closure equipped with a closure unit (24) making access to the openings (19) difficult, the closure unit (24) has at least two closure pieces (26) with radial branches, each of the at least two closure pieces (26) being attached and superimposed on a support shaft (25) and angularly offset from each other.
 37. The device according to claim 33, wherein the closure unit (24) is one of a complex arrangement of flat and wire-like forms.
 38. The device according to claim 36, wherein a supporting and reinforcing ring is attached to an upper portion of the closure unit (24) around the closure pieces (26, 28) to prevent latter closure pieces (26) from being at least one of forced and twisted by an exterior tool.
 39. The device according to claim 33, wherein an upper end of the plunger tube (8) has an attaching flange (13) by which the anti-theft, anti-intrusion, and anti-overflow device is attached to an orifice piece of the tank.
 40. The device according to claim 39, wherein the attaching flange (13) is surmounted by a second neck piece with an end flange (15) forming the new neck piece (16) defining the new tank filling orifice (4) for attaching the gas cap (5).
 41. The device according to claim 40, wherein the new neck piece (16) with the end flange (15) is connected to the attaching flange (13) on the tubular plunger (8) by solder points which are designed to break during an attempt to fraudulently extract the anti-theft, anti-intrusion, and anti-overflow device (1) from the original neck piece (3) of the tank (2).
 42. The device according to claim 40, wherein an upper portion of the attaching flange (13) has at least one passageway (53) therethrough, allowing any liquid present in a upper space of the tubular body (8) on an upper surface of the attaching flange (13) to flow back into the tank (2).
 43. The device according to claim 33, wherein the retractable filling tube (7) comprises a gripping means
 44. The device according to claim 43, wherein the retractable filling tube (7) is joined to the cap (5) by a connector.
 45. The device according to claim 33, wherein the retractable filling tube (7) comprises a safety closure (29) comprising a movable closure piece (30) to ensure closure of an upper opening of the retractable filling tube (7).
 46. The device according to claim 45, wherein the movable closure piece (30) is at least one of a folding piece, a removable interior piece and a removable exterior piece.
 47. The device according to claim 45, wherein the movable closure piece (30) is a pivotably mounted piece (31) pivotable about a longitudinal axle, and the pivotably mounted piece (31) is a flat piece having a shape similar to a shape of the upper opening of the retractable filling tube (7).
 48. The device according to claim 45, wherein a lower surface (38) of the movable closure piece (30) comprises a projecting stop (39) to stop the movable closure piece (30) when pivoting between an open and closed position.
 49. The device according to claim 45, wherein the movable closure piece (30) is a pivotable piece (40) that is pivotably attached about a transverse axle (41) on the retractable filling tube (7).
 50. The device according to claim 49, wherein a repelling force maintains the movable closure piece (30) in a closed position against a rim (42), that forms an interior shoulder within the retractable filling tube (7) that serves as a seating for the movable closure piece (30).
 51. The device according to claim 46, wherein the movable closure piece (30) is formed of two pivotable pieces facing each other (43, 44) each of the two pivotable pieces pivot about a respective transverse axle (45, 46) on the retractable filling tube (7).
 52. The device according to claim 51, wherein a repelling force maintains each of the two pivotable pieces (43, 44) in a closed position against a rim (42), the rim (42) forming an interior shoulder for the retractable filling tube (7) and serving as a seating for the two pivotable pieces (43, 44) of the movable closure piece (30), each of the two pivotable pieces (43, 44) having a staggered formation to ensure sealing between the two pivotable pieces (43, 44).
 53. The device according to claim 45, wherein the movable closure piece (30) is a pivotable piece (47) mounted to pivot about a central transverse axle on the retractable filling tube (7).
 54. The device according to claim 53, wherein a repelling force maintains the movable closure piece (30) in a closed position against a semi-circular (49) interior rim and a semi-circular exterior rim (50) forming an interior shoulder for the retractable filling tube (7) and which serves as a contact stop for the movable closure piece (30).
 55. The device according to claim 45, wherein the movable closure piece (30) is inseparably attached to the tank cap (5) with a flexible and deformable connector (22).
 56. The device according to claim 43, wherein the attaching flange (13) is prevented from pivoting on the original neck piece (3) of the tank (2) by a stop piece (55).
 57. The device according to claim 56, wherein the stop piece (55) is a flat clamp with a rounded end (56), an opposite extremity of which has a projecting wedged rim (57) extending perpendicular to a body of the clamp to engage in a slot and ensure blocking. 